Ryan Chamberlain, the target of a nationwide manhunt that ended near San Francisco's Golden Gate Bridge, had all the makings of a homemade bomb at his apartment, according to an affidavit released today.

The FBI says it found a "powdery, green substance" along with a model rocket motor, a glass jar containing batteries, a circuit board, ball bearings and other materials authorities believe were "designed to maim or kill a human being or human beings" during a search of Chamberlain's home on Saturday.

The materials were found in a messenger bag adjacent to Chamberlain's kitchen table, according to the criminal complaint.

The powdery green substance is believed to be explosive material and within the powder was a model rocket motor.

"The insertion of the model rocket motor into the green powdery substance is significant since rocket motors are known to 'burn' at extreme temperatures, creating an efficient method of fully igniting explosive material," the complaint stated.

It said the bag contained other "components necessary to comprise an IED" or improvised explosive device, according to the complaint. They included ball bearings and screws "believed to be intended as projectiles," an "electric match... a common igniter for IEDs," a wire extending from the glass jar to the metal lid of the jar, and a circuit board "configured as a remote-controlled receiver," according to the court document.

Chamberlain, 42, appeared in court today for the first time.

The explosives suspect, who was caught near the Golden Gate Bridge late Monday, was a “dangerous and desperate person,” officials said today.

“I think you can tell from Facebook and social media posts attributed to him,” San Francisco Police Chief Greg Sur said during a press conference.

As more details emerge about Chamberlain, the former political consultant, Sur urged other people who might know someone suffering from severe depression to come forward.

“If anybody knows anybody reported to be in a dark place or someone who may cause danger … please tell us,” he said at the press conference.

The FBI wouldn’t elaborate on what the suspect planned to do with the explosives.

“All I can say is there were particular items that were found when we executed the search warrant that caused us great concern,” FBI special Agent in Charge David Johnson said.

Johnson did not say where the FBI got the information about the explosives.

Sur said the suspect resisted arrest and “a struggle ensued,” but ultimately police were able “to get someone who was absolutely growing more desperate by the moment.”

A letter Chamberlain appears to have posted on social media Monday hours before his arrest suggested he was a lonely man fed up with life’s hurdles. He wrote about lost love, career struggles, chronic depression and problems with his mother, who he described as a “religious addict.”

He hinted at suicide but did not mention harming anyone else.

“You’re reading this. That means we probably don’t know each other anymore, and I owe everyone an explanation,” the letter said.